Rare earth magnets are often used in place of ferrite magnets as permanent magnets because of their better magnetic properties. To obtain a motor volume which is as small as possible the use of arc-shaped rare earth magnets is known. Usually these are attached directly to the yoke of the direct-current motor, with the aid of a glued or clamped connection for example.
For low-cost solutions, in which the volume of the motor does not have such a large part to play, instead of arc-shaped rare earth magnets, cuboidal-shaped rare-earth magnets are often employed. The use of cuboidal-shaped rare earth magnets however has a negative influence on the distribution of the magnetic flux in the motor, i.e. leads to an increase in the magnetic stray flux and thereby to a reduced motor torque.